The present disclosure relates to a battery cell, a battery cell module having the battery cell according to the disclosure, a method for producing the battery cell module, a battery having at least one battery cell module, and a motor vehicle which has the battery cell module and/or the battery.
There is a considerable need for batteries for a wide range of applications, for example for vehicles, stationary installations, for example in wind power installations, and mobile electronics devices, for example laptops and communications devices. Very high demands are made on these batteries in respect of reliability, service life and performance.
Lithium-ion technology is predestined for a wide field of use. It is distinguished, amongst other things, by a high energy density and an extremely low level of self-discharge.
Lithium-ion cells of this type usually comprise an electrode which can reversibly incorporate lithium ions in the course of so-called intercalation or can remove them again in the course of so-called deintercalation. The intercalation takes place during the process of charging the battery cell, and the deintercalation takes place during the discharging of the battery cell for the power supply of electrical units.
It is likely that, in future, new battery systems on which very high demands are made in respect of reliability, performance and service life will come into use both in stationary applications, for example in wind power installations, in vehicles, for example in hybrid vehicles and electric vehicles, and also in the consumer sector, for example in laptops and mobile telephones in this case.
Drive batteries in hybrid vehicles, plug-in hybrid vehicles and electric vehicles are usually of modular configuration. In this case, modules are formed from at least two individual battery cells, which are interconnected in series or in parallel, and said modules are, in turn, combined to form relatively large subunits which share, for example, a common cooling device. Usually, the entire battery is ultimately formed from two or more of these subunits, wherein these modules and subunits can also be arranged one above the other over several levels, in each case depending on the installation space available. Modern battery cells, specifically lithium-ion battery cells, but also lithium-polymer battery cells or else lead-acid rechargeable batteries, have the connection terminal on one of the sides of the battery, which side is usually called the top or upper face.
When interconnecting the individual battery cells to form modules, a so-called cell connector is often fitted from above. In the case of series production, welded (for example laser welding, ultrasonic welding, friction welding etc.) or riveted connections are preferably used for this.
The connection between the individual modules is also made by means of a module connector which is often configured and fitted in a similar way to the cell connector.
A battery cell or a so-called rechargeable battery pack, which is produced from several battery cells, is considered to be at the end of its service life when it only has a specific power left and/or a specific capacity and/or exceeds a specific internal resistance. In the case of power and capacity, this limit is usually approximately when 80% of the initial value is reached, that is to say of the maximum possible value of the battery cell or the rechargeable battery pack. These limit values define the end of service life.
For reasons of efficiency, the battery cell in question or the rechargeable battery pack in question then has to be replaced. This replacement process, together with the process of connecting still functional battery cells to new battery cells, is relatively complicated and therefore cost-intensive.
KR 10 2006 018 326 A discloses a system for interconnecting battery cells, wherein a first terminal of a battery cell has a threaded bolt, and a second terminal of the battery cell has a cylindrical bolt. A cell connector can be plugged onto the cylindrical bolt and can be welded to the cylindrical casing surface of the bolt. A further cell connector can be plugged onto the threaded bolt and can be fixed there by means of a suitable screw connection, for example by means of a nut. Several battery cells can be connected using cell connectors of this kind in order to produce a battery cell module. However, when individual battery cells have to be replaced, the screw connection and/or the welded connection has to be broken again and it may be necessary to provide and install a new cell connector for connecting a remaining battery cell to a new battery cell.